Heretofore, it has been known that fiberglass may be successfully used for automotive bodies. When properly constructed, utilizing state-of-the-art techniques for strengthening and reinforcing, fiberglass structures for automotive use have been well received, providing the desired strength and beauty for such applications while being virtually uneffected by rust, corrosion, or the elements. Indeed, replacement fiberglass bodies for various automotive vehicles have become known in the art. The invention herein particularly relates to such replacement fiberglass bodies for the American Motors models designated as Jeep CJ5 and CJ7. While fiberglass bodies have previously been manufactured and provided for these specific models, such structures have not incorporated an interlocking outer body shell with a finished interior shell. Additionally, the known replacement fiberglass bodies for these Jeep models have not incorporated a unitary interior shell, but have required seams which are given to breaking, leaking, lack of rigidity, and other undesired features. Further, no known replacement fiberglass bodies for these models have included means for encasing an insulative material between the inner and outer shells and to do so by the placement of a unitary interior shell.